Process simulation of a dual-stage Selexol process for 95% carbon capture efficiency at an integrated gasification combined cycle power plant

Abstract

a b s t r a c tIt was aimed to simulate a conventional dual-stage Selexol process for removing CO 2 and H 2 S simultaneously from a synthesis gas (syngas) originated from a typical Integrated Gasification Combined Cycle (IGCC) power plant driven by a dry-coal fed gasifier using Honeywell UniSim R400. The solubilities of syngas components on Selexol were predicted by temperature-dependant Henry's law constants being newly evaluated in this study based on the experimental data in Xu et al. (1992). The operating conditions of the dual-stage Selexol unit were determined so as to meet simultaneously various performance targets, such as 99+% H 2 recovery, 90% CO 2 recovery, 99+% H 2 S recovery, and less than 20 ppm H 2 S in CO 2 product. By and large the resulting energy consumptions of the Selexol process were in good agreement with those reported in DOE NETL (2010) that this study was based on. It was shown that the integrated dual-stage Selexol unit could achieve 95% carbon capture rate as well as 90% by simply changing the operating conditions. By contrast a CO 2 removal Selexol process having not an input of lean solvent generated by thermal regeneration could not achieve 95% carbon capture rate due to a pinch point formed at the top of the CO 2 absorber.

Biomass gasification for bioenergy

“…The primary downsides of Rectisol are that it is mostly applicable to large-scale plants and that it requires a refrigeration plant consuming electricity. Other commercial gas cleaning processes for sulphur and/or CO2 include Selexol and Purisol (Kapetaki et al, 2015;Vitasari et al, 2011).…”

“…After synthesis, a part of the gas is recycled, and the raw SNG product is purified from CO2 and water dilution. While water is removed via cooling, pressurized gas washes such as the commercial Selexol process are mostly used (Kapetaki et al, 2015;Vitasari et al, 2011). After purification, the SNG is compressed to the local natural gas grid pressure level and directly injected into the grid.…”

More Energy-Efficient CO2 Capture from IGCC GE Flue Gases

“…According to the literature review on other CO 2 capture processes, it is obvious that dual-stage Selexol processes have been recognized as the most conventional processes for recovering H 2 S and CO 2 simultaneously [13]. For the design of acid gas removal processes using Selexol solvents, Kohl and Nielsen [14] exhibited a simple two-stage Selexol process composed of one set of an absorber and steam stripper for H 2 S removal followed by another set of an absorber and air stripper for CO 2 removal.…”

“…Bhattacharyya et al [16] implemented a comprehensive process simulation of an entire IGCC power plant integrated with a dual-stage Selexol process for a 90% overall carbon capture efficiency with the performance as shown in Table 5. Table 5 shows the energy consumption of the process, as extracted from Kapetaki et al [13], as well as a comparison between the energy consumption of the dual-stage Selexol process and that of the cryogenic energy-saving scheme as described earlier in Table 4.…”

Adsorptive cyclic purification process for CO2 mixtures captured from coal power plants

“…At present, with respect to capturing CO 2 from huge amounts of CO 2 /N 2 emission gases, sorption processes are generally recommended for post‐combustion CO 2 capture from coal power plants . Several CO 2 capture technologies using wet solutions and dry sorbents have been demonstrated at actual sites …”